Conventionally, as a technique for restricting access to so-called harmful sites (Web pages), a communication terminal has been proposed in which access to sites on the Internet is limited to only bookmarks that have been registered by a person with parental authority (see Patent Document 1, for example).
Additionally, a method has been proposed in which a slave machine is allowed to access sites only via a master machine and transmission of information from the site to the slave machine is restricted by the master machine side (see Patent Document 2, for example).